基于FDTD的高保真SAR回波信号仿真方法

针对传统合成孔径雷达(synthetic aperture radar, SAR)回波仿真算法忽略目标散射特性在观测时间内随方位角度和信号频率变化这一问题,提出一种基于时域有限差分方法(finite--difference time-domain method, FDTD)电磁散射计算的SAR原始回波数据生成方法,在此基础上提出了基于服务器的并行仿真策略及流程。该方法利用FDTD算法及后续仿真处理精确模拟了SAR系统线性调频脉冲信号从卫星传感器发射后,与场景目标发生相互作用,再被SAR系统传感器接收并生成原始回波数据的全部物理过程,从而得到高保真的SAR原始回波数据。最后,通过典型目标时间谱与空间谱的仿真对比实验及最终成像结果证明了本文所提算法的正确性及有效性。

High-precision simulation of SAR echo using FDTD method

Considering the diversity of target scattering characteristics with different observation condition and signal frequency is ignored in traditional simulation of synthetic aperture radar (SAR) echo, a high-precision simulation method based on finite-difference time-domain method (FDTD)technology is proposed in this paper. In addition, the strategy and scheme of parallel simulation based on server are presented. The physical forming procedure of SAR echo, including the transmission of chirp signal, the interaction with target and the receiving of echo, were accurately simulated by using the proposed method and then obtain high-precision SAR echo. Through simulation experiments of space-spectrum, time-spectrum and image results, the validity and effectiveness of the proposed method is verified.